This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. There is no doubt that the nervous system is targeted in a high proportion of patients with acquired immunodeficiency syndrome (AIDS). Estimates are that at least 50% and possibly up to 90% of the patients will experience some manifestations of peripheral (PNS) or central nervous system (CNS) dysfunction. In 1998, the National Institutes of Health funded the National NeuroAIDS Tissue Consortium to develop and maintain repositories around the country and promote research in the area of CNS dysfunction. The overarching objective is to provide a critical resource that will assist researchers around the world in elucidating mechanisms involved with neuropsychiatric problems in patients with AIDS. The aims are : 1) obtain pertinent clinical, laboratory and historical information prior to the subject's demise;2) assess the subject's performance on objective neuropsychiatric assessments using uniform protocols;3) objectively document each subject's drug use histories;4) obtain proper authorization for autopsy at the subject's demise;5) provide excellent autopsy services using rigidly-defined mechanisms for brain specimen collection and handling;6) maintain a secure mechanism of database management to provide pertinent information anonymously to investigators;7) maintain a state-of-the-art specimen banking facility with carefully defined biohazard containment and specimen preservation during storage, transport, and distribution to the research community. This is an observational longitudinal study with subjects evaluated every 6 months to 2 years depending on health status. This research distributes tissue samples to researchers around the world and also makes available testing data collected prospectively on research subjects.